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| author | Paolo Bonzini <pbonzini@redhat.com> | 2012-06-13 07:41:28 +0200 |
|---|---|---|
| committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2012-06-21 17:59:27 -0500 |
| commit | eab5fd5989a1ac48d123ccaec7346ce325b9ee77 (patch) | |
| tree | 2552c109491a2b1070b306bd6dcead17622de0dc /qapi-schema-guest.json | |
| parent | af02203fbe03f0634fea26a6e30febdeed14ede9 (diff) | |
qemu-ga: add guest-fstrim command
FITRIM is a mounted filesystem feature to discard (or "trim") blocks which
are not in use by the filesystem. This is useful for solid-state drives
(SSDs) and thinly-provisioned storage. Provide access to the feature
from the host so that filesystems can be trimmed periodically or before
migration.
Here is an example using scsi_debug:
# modprobe scsi_debug lbpu=1 lbpws=1
# sg_vpd -p0xb2 /dev/sdb
Logical block provisioning VPD page (SBC):
Unmap command supported (LBPU): 1
Write same (16) with unmap bit supported (LBWS): 1
Write same (10) with unmap bit supported (LBWS10): 0
# mke2fs /dev/sdb
# cat /sys/bus/pseudo/drivers/scsi_debug/map
1-616,16257-16383
# mount /dev/sdb /run/media/pbonzini/test
# dd if=/dev/zero of=/run/media/pbonzini/test/file
# cat map
1-616,645-1588,1599-4026,4029-16383
# rm /run/media/pbonzini/test/file
# ./qemu-ga /dev/fd/0
{"execute":"guest-fstrim"}
{"return": {}}
# cat map
1-612
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Diffstat (limited to 'qapi-schema-guest.json')
| -rw-r--r-- | qapi-schema-guest.json | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/qapi-schema-guest.json b/qapi-schema-guest.json index d4055d262a..d955cf11fb 100644 --- a/qapi-schema-guest.json +++ b/qapi-schema-guest.json @@ -351,6 +351,26 @@ 'returns': 'int' } ## +# @guest-fstrim: +# +# Discard (or "trim") blocks which are not in use by the filesystem. +# +# @minimum: +# Minimum contiguous free range to discard, in bytes. Free ranges +# smaller than this may be ignored (this is a hint and the guest +# may not respect it). By increasing this value, the fstrim +# operation will complete more quickly for filesystems with badly +# fragmented free space, although not all blocks will be discarded. +# The default value is zero, meaning "discard every free block". +# +# Returns: Nothing. +# +# Since: 1.2 +## +{ 'command': 'guest-fstrim', + 'data': { '*minimum': 'int' } } + +## # @guest-suspend-disk # # Suspend guest to disk. |